1. Field of the Invention
The present invention relates to a parking brake and more particularly to a parking brake for an automatic transmission mechanism.
2. Description of the Prior Art
Generally, a vehicle mounted with an automatic transmission mechanism is established with a transmission range covering parking (P), reverse driving (R), neutral (N), driving (D) and the like.
When a change lever at the transmission range is positioned at a parking range, an output axle is mechanically restricted to allow a vehicle to maintain a parking state, but in order to maintain the parking state a separate parking mechanism is needed.
As illustrated in FIGS. 4 and 5, the separate parking mechanism includes a change lever assembly 51 where a change lever 50 is so disposed as to be movable to each range, a manual lever 54 protrusively disposed at a transmission case 52 and internally connected by a detent plate 53, a control cable 55 connecting the change lever assembly 51 and the manual lever 54, a parking rod 56 connected at one end thereof to the detent plate 53 for slideable movement, a parking lever 58 connected at one end thereof to the parking rod 56 for rotation by way of a hinge shaft 57 and a parking gear 60 intermittently restricted by the parking lever 58 and so mounted as to be cooperatively connected to an output shaft 59.
Furthermore, the parking lever 58 is provided with a spring 61 which is supported at one end thereof by a fixed portion and is connected thereto at the other end thereof, such that the parking lever 58 is always detached from the parking gear 60 to apply resilience thereto.
In other words, the parking lever 58 is rotatably moved to intermittently restrict the parking gear 60, and when the parking gear 60 is restrained, the output shaft 59 is put to a restricted state to allow a vehicle to maintain the parking.
Now, operation of the parking brake mechanism thus described will be explained.
When a driver shifts the changer lever 50 to a parking (P) position to park a vehicle, the control cable 55 rotates the manual lever 54 and simultaneously rotates the detent plate 53 connected thereto. When the detent plate 53 is rotated, the parking rod eccentrically connected thereto is moved to the right direction on the FIG. 4.
When the parking rod 56 is moved to the right side, the parking lever 58 adhered to a tip end of the parking rod 56 is rotated clockwise about the hinge shaft 57, where a tip end of the parking lever 58 is inserted into gear grooves of the parking gear 60. When the parking lever 58 is inserted into the gear grooves of the parking gear 60 to thereby prevent the parking gear 60 from rotating, the output shaft 59 where the parking gear 60 is fixedly disposed is refrained from rotating, thereby causing the vehicle to maintain the parking state.